Door lock mechanism

ABSTRACT

A DOOR LOCK MECHANISM COMPRISING A BASE MEMBER FIXEDLY MOUNTED ON A DOOR OF AN AUTOMOTIVE VEHICLE, A RECESS FORMED ON THE BASE MEMBER AND HAVING AN ARCSHAPED PERIPHERY DEFINING PART OF THE CONFIGURATION OF THE RECESS, A SECTOR LATCH MEMBER PIVOTABLY MOUNTED IN THE RECESS, THE LATCH MEMBER FORMED WITH AN ARC-SHAPED PERIPHERAL PART HAVING THE SAME RADIUS AS THAT OF THE ARCSHAPED PERIPHERY OF THE RECESS. A SPRING URGING THE LATCH MEMBER TO ROTATE IN ONE DIRECTION WITH A CHECKER ROTATABLY MOUNTED ON THE BASE, A SECOND SPRING URGING THE CHECKER TO ROTATE IN A DIRECTION OPPOSITE TO THE ONE DIRECTION. A   FIRST AND A SECOND TOOTH IS FORMED ON THE LATCH MEMBER FOR COOPERATING IN SUCCESSION WITH THE FIRST AND SECOND TOOTH TO KEEP THE LATCH MEMBER IN ITS SAFETY LATCH AND FULL LATCH POSITION, AND A SECOND AND SUBSTANTIALLY RADIALLY DIRECTING RECESS FOR COOPERATING RECEIVING A STRIKER IS MOUNTED ON A STATIONARY PART OF THE VEHICLE WHEN THE DOOR IS OPERATED IN ITS CLOSING DIRECTION.

Jun 6, 1972 KENICHI KAZAOKA ETAL 3,

DOOR LOCK MECHANISM 3 Sheets-Sheet 1 Filed F'eb. S), 1970 FIG.2

FIG.

June 7 KENICHI KAZAOKA ETAL 3,66

DOOR LOCK MECHANISM 3 Sheets-Sheet 2 Filed Feb. 9, 1970 FIG.7

DOOR LOCK MECHANISM 3 Sheets-Shoot 5 Filed Feb. 9, 1970 FIG.||

FIG.IO

United States Patent Oifice 3,667,791 Patented June 6, 1972 US. Cl.292-216 9 Claims ABSTRACT OF THE DISCLOSURE A door lock mechanismcomprising a base member fixedly mounted on a door of an automotivevehicle; a recess formed on the base member and having an arcshapedperiphery defining part of the configuration of the recess; a sectorlatch member pivotably mounted in the recess, the latch member formedwith an arc-shaped peripheral part having the same radius as that of thearcshaped periphery of the recess. A spring urging the latch member torotate in one direction with a checker rotatably mounted on the base; asecond spring urging the checker to rotate in a direction opposite tothe one direction. A first and a second tooth is formed on the latchmember for cooperating in succession with the first and second tooth tokeep the latch member in its safety latch and full latch position; and asecond and substantially radially directing recess for cooperatinglyreceiving a striker is mounted on a stationary part of the vehicle whenthe door is operated in its closing direction.

BACKGROUND OF THE INVENTION Field of the invention This inventionrelates to improvements in and relating to door lock mechanisms for usewith automotive vehicle doors.

SUMMARY OF THE INVENTION It is an object of the invention to provide arigid, compact and efficient door lock mechanism adapted for bearingevery directional outside forces of substantial magnitudes acting on thedoor lock mechanism, especially in the axial, lateral and verticaldirections, even in an emergency.

It is a further object of the invention to provide a door lock mechanismof the above kind, capable of functioning in a more stabilized andefficient manner than the conventional comparative mechanisms, althoughthe door lock mechanism according to this invention has only a limitedspace requirement.

BRIEF DESCRIPTION OF THE DRAWINGS These and further objects, featuresand advantages of the invention will become more apparent when read inthe following detailed description of the invention by reference to theaccompanying drawings illustrative by way of example two preferredembodiments of the invention.

In the drawings:

FIG. 1 is a front view of a preferred first embodiment of the door latchmechanism in its normal or off-service position with the automotivedoor, not shown, being kept open.

FIG. 2 is a similar view to FIG. 1, wherein, however, the door lockmechanism is shown in its safety latch position, as met with the doorpositioned in its almost closed state.

FIG. 3 is a similar view to FIG. 1, wherein, however, the door lockmechanism is shown in its full latch position, as met with the doorpositioned in its closed position.

FIG. 4 is a sectional view taken along a sectional line IV-IV shown inFIG. 3.

FIGS. 5 and 6 are respective perspective views of a checker and astriker.

FIGS. 7-10 are similar views to FIGS. 1, 2, 3 and 4, yet showing asecond embodiment of the invention.

FIG. 11 is a similar view to FIG. 10, wherein, however, a substantialexternal force is being applied to the mechanism.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to theaccompanying drawings, several preferred embodiments of the inventionwill be described in detail.

In FIGS. 1-4, the numeral 10 denotes a base member, preferably made of arigid plastic material such as polycarbonate, phenolic or the likeresin, and having substantially a rectangular configuration when seen ineach of FIGS. 1-3.

The base member 10 is made substantially into a plate having a thicknessof several millimeters and provided with a peripheral reinforcing rib10a. The base 10 is further formed with a plurality of, four in thispreferred embodiment, bolt holes 11 adapted for attachment to a door ofan automotive vehicle, not shown.

A substantially segmental latch member 12 is pivotably mounted around aprojection or pin 13 having its center at 14 and made integral with saidbase 10 which is formed with a recess 15 having substantially the formof a half moon. The latch member 12 is formed with an arc-shapedperipheral edge 12a having a radius R measured from the center 14 of thepin 13, said peripheral edge 12a being kept in slidable engagement witha correspondingly formed arc-shaped peripheral edge 15a defining part ofsaid recess 15 and having the same radius R measured from said center14. The peripheral edge 15a is interrupted at its intermediate point bythe provision of a round recess 16 formed in the base member 10 andreceiving rotatably the enlarged head 17a of a checker 17. The pin head17a is recessed at 17b as most clearly seen from FIG. 5 and the checker17 has a concentric stem 17c which passes rotatably and projectinglythrough a bore 18 drilled through the body of base member 10. As seenfrom FIG. 4, the bore 18 is provided concentrically with the roundrecess 16.

For allowing the latch 12 to perform pivotal movement, the latch isformed with a rounded recess 12b which is concentric with the arc-shapedouter periphery 12a and kept in slidable contact with pivot pin 13.

The recess 15 is formed with an arc-shaped groove 19 in which an urgingcoil spring 20 is positioned. With one end of this spring 20, a pin 21is kept in engagement. As seen from FIG. 4, this pin 21 is made integralwith the body of latch 12, the latter being therefore resiliently urgedto turn in clockwise direction when seen in FIGS. 1-3. The spring 20 isnaturally mounted in position with a certain predeterminedprecompression.

The latch 12 is provided with a straight edge 12c which is kept inpressure engagement with a straight edge portion 15b forming a part ofthe overall wall part defining the general configuration of the recess15 when seen in FIGS. 1-3. The design and arrangement of said groove 19,latch 12, recess 15 and pin 21 are so selected that with the latch 12positioned in its off-service position shown in FIG. 1, there is a smallidle gap between the pin 21 and the neighboring end wall of said groove19.

The latch 12 is formed with a first tooth surface 12d and a second toothsurface 12e at a small mutual distance as shown. These tooth surfacesare so designed and arranged that when the latch is rotatedcounterclockwise from the position shown in FIG. 1, they are broughtinto successive engagement with tooth-like portion 23 which is formed onthe recessed head 17a of the rotatably mounted checker 17, as will beeasily understood when observing FIGS. 2 and 3, respectively.

The latch 12 is formed with a substantially radially directing recess ornotch 24 so as to provide a projecting arm 25, said notch beingcooperatable with a conventional striker 26, as will be more fullydescribed hereinafter. The striker 26 is shown specifically in FIG. 6.

In FIG. 6, the striker 26 comprises a disk-like main body 26a which isformed in turn with two bolt holes 27 and 28 for the fixed attachment tothe main body, preferably pillar means thereof, not shown, of a vehicle.Although conventional striker is provided with a striker pin, the doorlatch mechanism according to this invention, as exemplified, is fittedrigidly with a modified striker proper into a U-shaped member 29 asshown.

As shown in FIG. 4, a latch-release lever 30 is rigidly fixed at its oneend with the projecting stern 170 of checker member '17 by conventionalfixing means such as riveting as shown. A tension spring 31 is tensionedbetween a stop pin 32 rigidly mounted on base member 10, and thelatch-release lever 30, thus urging the assembly comprising said lever30 and the checker 17 to turn counter-clockwise in FIG. 3.

With the lever 30 turned in the clockwise direction in FIG. 3, thetension of the spring 31 is correspondingly increased so that thecounterclockwise turning effort being applied on the lever will becomecorrespondingly increased. It should be however noted that a certaininitial tension is applied and thus, even when the lever 30 ispositioned at its rest position shown in FIG. 3, where the lever abutsagainst a stop pin 32 rigidly attached on the back surface of the basemember 10, with the spring 31 kept in its least tensioned state, thelever is being subjected to a certain amount of counterclockwise turningeffort when seen in FIG. 3.

The base member 10 is further formed with an elongated passage recess,generally shown at 33, which has an enlarged part 33a as shown, a guidepin 36 bridges the left and right hand end wall parts 331: and 330. Aslide block 34 is mounted slidably on the guide pin 36, said slide beingurged resiliently to move along the pin from right to left in FIGS. 1-3by virtue of the provision of an urging coil spring 35 which is mountedaround the guide pin and inserted between the slide block 34 and thewall part 33c. As will become more clear hereinafter, the passage recess33 is arranged to receive the striker per se and the slide block 34functions to assure more positively the latched position of the latchmechanism when operated. In the off-service position or so of the latchmechanism, the slide block 34 is kept in its lefthand extreme positionshown in FIGS. 1 and 2, where the slide abuts against the left-hand sidewall 33b defining a part of the enlarged recess part 33a. Any turningmovement of the slide block 34 around guide pin 36 is positivelyprevented by forming the rear surface of said slide into a plane surfacekept in slidable contact with a correspondingly plane surface formed onthe base member 10.

The door plate to which the main parts of the door latch mechanismcomprising said base member 10 fixedly attached is shown onlyschematically in FIG. 4 by two parallel chain-dotted lines The operationof the first embodiment of the door latch mechanism so far shown anddescribed is as follows:

As referred to hereinbefore, the position of the door latch mechanismshown in FIG. 1 is the unlatched or latch-release one, thus the doorbeing kept in its open position. When a driver or the like personoperates the open door in its closing direction, the striker 26 fixedlyattached to the automotive body and together with its latching member 29will relatively approach towards the advance into passage recess 33. Themember 29 will then be brought into collision with arm 25, thereby thelatch 4 member 12 being rotated in the counter clockwise directionaround the pivot pin 13 against the urging force exerted by thecompression spring 20 through the intermediary of motion-receiving pin21 upon the latch with its outer peripheral edge 12a performing asliding motion on the arc-shaped wall 15a of recess 15.

Since checker 117 is always urged resiliently by tension spring 31 toturn counterclockwise in FIGS. 1-3, the tooth-like portion 23 on thechecker is brought into engagement with first tooth surface 12d, afterthe latch 12 has been rotated a predetermined angle from the positionshown in FIG. 1 to that shown in FIG. 2. In FIG. 2, this engagedposition between the both is clearly demonstrated, which corresponds tothe safety latch position so-called by those skilled in the art.

With further door-closing operation and thus with further advancingmovement of the latching member 29 from left to right, from the positionshown in FIG. 2 to that shown in FIG. 3, the latch 12 is further rotatedin the counter-clockwise direction as before, and the provi sionallyestablished engagement between 12b and 23 is released and a newengagement is brought about between 122 and 23, as shown in FIG. 3. Atthe same time, the lever 30 is urged into engagement with stop pin 32 bythe spring 31 and therefore, any further counterclockwise rotation ofthe checker 17 and clockwise rotation of the latch 12 is positivelyprevented. During straight invading movement of the latching member 29along the passage recess 33, more specifically its enlarged inner endpart 33a, the member 29 will be brought into pressure contact with theinclined, motion-receiving surface at 34a of the slide block 34 and ridetherealong so that the latter is moved forcibly towards right in FIG. 2,against the urging force exerted by compression spring 35. At the almostfinal stage, the mutual position of latch 12, latching member 29 andslide block 34 will be that shown in FIG. 3, this engaged position beingcalled the full latch position.

The automotive door can be operated to a certain small degree in itsclosing direction. With this movement, the latching member 29 canadvance only a small distance in the right-hand direction from theposition shown in FIG. 3. But, the base member 10 is so designed andarranged that it is kept in contact with a conventional weather strip,not shown, provided on the vehicle body, for limiting this kind ofexcess movement of the door or latching member 29 to only a smalldistance.

When any unintentional outside or inside force is applied to the thuslatched door, and thus the latching member 29 is subjected to a forcefor moving leftwards in FIG. 3 from the position shown therein, thelatch 12 is exerted upon by a corresponding force directing in the samesense by virtue of the latched engagement between the both. In thiscase, however, the thus urged latch 12 is prevented from its moving inthat direction by virtue of the broad contact between the arc-shapedouter periphery 12a and the correspondingly shaped recess-defining wallsurface at 15a. A clockwise rotation of the latch 12 urged at the sametime by the door-opening force is also prevented in a positive manner,because in this position the tooth-like portions 23 on checker 17 iskept in engagement with the second tooth 12a of the latch 12.

As commonly known, a hinged door such as the automotive door hasdisadvantageously a tendency of hangingdown by its own weight. Apositive prevention of such hanging-down of the door is brought about byuse of the door latch mechanism according to this invention wherein withthe door closed, the channel-shaped striker proper 29 is brought intopositive engagement with the upper wall 36b defining the upper limit ofthe groove 33', thus the door being definitely supported through thebase gilecr tnbgr 10 by the striker as will be clearly seen from When,as an example, a vehicle should come into collision in the lateraldirection and against the body of the vehicle fitted with the presentdoor latch mechanism a substantial force will act in the longitudinaldirection of the vehicle body, thus tending the latch member 12 beingforcibly moved in the axial direction of pivot pin 13, or morespecifically in the perpendicular direction to the drawing paper surfaceof FIG. 3 and towards the viewer by the striker proper 29. In this case,the engagement of the second tooth 122 with the checker tooth 23 will bereleased and the latch 12 will move in the aforementioned direction,but, in the mechanism so far shown and described, an excess displacementof the latch would be positively prevented by contact with the rearsurface of the door plate 5'0, to which the base member of the doorlatch mechanism is fixedly attached by bolts, not shown, which arescrewed in position after passage through the bolt holes 11, as wasbriefly hinted hereinbefore. Therefore, it will be easily understoodthat the latch member is not removed from position in this case, shouldthe door latch not be subjected to destruction.

When it is desired to open the door from its closed position with theconstituent parts of the latch mechanism positioned as shown in FIG. 3,lever 30 is turned in the clockwise direction in FIG. 3 against theurging force exerted by the spring 31, so as to rotate the checker 17 inthe same direction and in unison with the lever and to release theengagement between 23 and 12e. Thus, the latch 12 is rotatedautomatically in the clockwise direction in FIG. 3 under the action ofthe biasing spring 20. Therefore, the latch 12 will be returned from theposition shown in FIG. 3 to that shown in FIG. 2, or directly to theposition shown in FIG. 1.

The first embodiment shown and described so far has the followingseveral advantages.

Since the latch 12 has been formed into substantially a sector shape,the radius R extending from the center 14- of pivot pin 13 to thearc-shaped outer periphery 12a of the latch can be selected toaconsiderably large value in comparison with that adopted in acomparatively compact design of the door lock mechanism. In effect, thedistance shown at B1 in FIG. 3 can be increased considerably whencompared with the similar part in the conventional mechanism, even withsuch assumption that the thickness of the latch be identical with eachother. By adopting this measure, the durable performance of the latch 12against the forced shift of the striker leftwards in FIG. 3 by virtue ofan unintentional application of a sudden and substantial door-openingforce, as may be met in an emergency.

By the adoption of a larger value of the radius R, the contact area ofthe arc-shaped outer periphery of the latch with the similarly shapedrecess-defining wall part of the base plate 10, providing a broaderpressure transmitting area of the latch member acting against possiblemovement of the striker urged unintentionally and forcedly in thedoor-opening direction, as may be encountered in an emergency, therebyconstituting a substantially rigid door latch mechanism. In a preferredembodiment as the present one, the ratio: R/C shown in FIG. 3, whereinthe distance C is that measured from the center 14 of pivot pin 13 tothe central axis of the locus of the striker per se 29 when the striker26- moves relative to the base member 10 in the aforementioned way, isselected to be substantially equal to that employed in the conventionalcomparative mechanism, even for a larger value of said distance C, theacting pressure between the both teeth -12e and 23 which appears whenthe latch member 12 is rotated in the aforementioned way, Will besubstantially equal to that conventionally adopted. Therefore, thedimensional requirement for the checker 17 and its related parts servingfor returning the latch from the position shown in FIG. 3 to that inFIG. 1 may not be unchanged for attaining equal strength asconventional.

Next, referring to FIGS. 7-11, a preferred second embodiment of theinvention will be described in detail.

The reference symbol 10' is a similar base member to that shown at 10 inthe foregoing, said base being formed equally with a peripheralreinforcing rib 10a as well as four bolt holes 11' as before.

A segmental latch member 12' is also provided which is rotatably mountedaround a fixed pivot pin 13', yet through the intermediary of a firstbushing 40 made of a resilient material, such as hard rubber or thelike, and a second concentric smaller diameter bushing 41 made of metalor metal alloy having a small frictional coefficient. The first bushing40 is fixed to the latch 12, while the second bushing 41 is rotatablerelative to the first bushing and the pivot pin 13, said pin 13 beingequal design as that shown at 13 in the foregoing embodiment. As before,the latch 12 has an arc-shaped peripheral edge 12a having a radius Rmeasured from the center 14' of the pivot pin 13. The latch 12' isrotatably and slidably mounted on the bottom of a mounting recess 15having an arcshaped peripheral wall 15a having an equal radius as R, butits center is offset a small distance from the said center 14', saidoffset distance being naturally equal to the gap at g between the latchperipheral edge 12a and the recess-defining peripheral Wall 1511'. Thegap g is maintained normally, so far as the first bushing 40 keeps itsregular cylindrical shape as shown in FIGS. 7-9. As seen, the wallthickness of the first or elastic bushing 40 is substantially largerthan the dimension of said gap g. The material of the elastic bushing 40has a rather substantial rigidity so that the bushing may be elasticallydeformed only when a substantial lateral force, when 'seen in FIGS. 7-9,as met in a vehicle collision or the like emergency accident, should beapplied to the latch mechanism, as will be more fully describedhereinafter by reference to FIG. 11.

Several other parts, such as shown at 12b, 12c, 12d, 122', 151), 16',17', 17a, 17b, 17c, 18', 19', 20', 21', 22', 23, 24', 25, 26', 29', 30',31, 32', 33', 33a, 33b, 33c, 34, 35', 36, 50' have substantially samedesign and function as those denoted with same reference numeralswithout attaching no prime, shown and described in the foregoing firstembodiment. Therefore, no further analysis of the second embodimentwould be necessary for the understanding thereof.

In the normal operation of the door lock mechanism, the latch 12'rotates in one or the other direction as before, but, without slidingcontact of its arc-shaped outer peripheral edge 12a with thecorrespondingly arc-shaped wall part 15a of the mounting recess 15, thusthe gap g being maintained for smooth rotation of the latch.

On the contrary, if a sudden and considerable dooropening force shouldact in the door-opening direction, by way of example, in an emergency,and thus the striker proper 29 is moved suddenly from right to left inFIG. 9 with the latch mechanism kept in its full latch position showntherein, the latch 12 is pushed leftwards and the elastic bushing 40will be subjected to deformation as shown in FIG, 11 and the latch 12will be brought into direct contact with the arc-shaped peripheral wallpart 15a of the recess 15, thus the gap g disappearing and thedoor-opening force being borne by the direct abutment between the latchand the base member. Therefore, in this case, the broad engagementsurface of said areshaped wall part 15a serves for bearing the intensivedoor-opening force. In this case, even when the latch 12' is subjectedto clockwise rotation, the already established engagement between thetooth parts 12e' and 23', will effectively prevent such latch rotation,if not the dooropening force should be so large that the door latchmechanism may be destroyed.

In the present embodiment, the pivot pin 13 may be of slender designthan that employed in the foregoing embodiment, because a severedoor-opening force can not be borne by the pivot pin, thanks to theprovision of the elastic bushing 40.

Other functions of this second embodiment are substantially similar tothose in the first embodiment, so that no further analysis thereof wouldbe necessary for better understanding of the invention.

The embodiments of the invention in which an exclusive property orprivilege is claimed are as follows:

1. In a door lock mechanism for a vehicle door comprising a base memberfixedly mounted on said vehicle door and having a curved wall recessalong one side thereof;

a latch member pivotably mounted in said recess and having a secondrecess;

a striker mounted rigidly on a stationary part of said vehicle, andadapted to enter on said same side as said recess of said base member,said second recess capable of engagingly receiving said striker;

a checker means pivotably mounted on said base member for locking saiddoor by engagement with said latch member, said latch member having agenerally sector-shaped configuration with an are shaped outerperipheral surface, said curved wall recess having an are shaped wallsurface complementary to said latch member peripheral surface so thattheir radii are substantially the same dimension, whereby said twosurfaces can engage along a major portion of their surfaces upon thetransmission of a large force from said striker to said latch memberduring and after a door locking operation and while said door is in itsclosed position, and

a pivot pin rigidly mounted on said base member, said latch member beingpivotably mounted on said pivot pin and supported against a door closingforce transmitted from said striker to said latch member when said dooris being closed, said arc shaped wallsurface of said base membersupporting said latch member against a door opening force transmittedfrom said striker to said latch member.

2. The door lock mechanism as claimed in claim 1,

further comprising:

a groove formed on said base member, and

a spring inserted in said groove, one end of said spring being kept inpressure engagement with said latch member so as to urge the latter tomove in the dooropening direction.

3. The door lock mechanism as claimed in claim 2, further comprising asecond spring mounted on said base member and acting upon said checkermeans which is thereby urged to move in a direction for engaging withsaid latch member.

4. In a door lock mechanism for a vehicle door comprising a base memberfixedly mounted on said vehicle door and having a curved wall recessalong one side thereof;

a latch member pivotably mounted in said recess and having a secondrecess;

a striker mounted rigidly on a stationary part of said vehicle, saidsecond recess capable of engagingly receiving said striker;

a checker means pivotably mounted on said base memher for locking saiddoor by engagement with said latch member, said latch member having agenerally sector-shaped configuration with an are shaped outerperipheral surface, said curved wall recess having an are shaped wallsurface complementary to said latch member peripheral surface, with theradius of said curved wall recess being slightly larger than the radiusof said latch member peripheral surface, whereby the two surfaces willengage only upon the transmission of a large force form said striker tosaid latch member after a door locking operation and while said door isin its closed position;

a pivot pin rigidly mounted on said base member, and

elastic bushing means connecting said pivot pin to said latch member forabsorbing the normal forces transmitted between said latch member andsaid base member during a normal door locking operation.

5. The door locking mechanism as claimed in claim 4, where said elasticbushing means further includes a first elastic bushing fixedly mountedon said latch member and a second bushing rotatably mounted on saidpivot pin and connected to said first elastic bushing.

6. The door lock mechanism as claimed in claim 5, further comprising aspring biased camming member directly engaging said striker in a closeddoor position to help support said striker.

7. The door lock mechanism as claimed in claim 5, where the firstelastic bushing has a thickness capable of resiliently being deformed toabsorb normal door locking operation forces between said base member andsaid latch'member without said curved wall recess surface contactingsaid latch member peripheral surface, the resilient thickness, however,not preventing the engagement of said surfaces upon the occurrence ofextraordinary forces beyond normal door locking operation forces.

8. The door lock mechanism as claimed in claim 4, further comprising:

a groove formed on said base member, and

a spring inserted in said groove, one end of said spring being kept inpressure engagement with said latch member so as to urge the latter tomove in the dooropening direction.

9. The door lock mechanism as claimed in claim 4, further comprising asecond spring mounted on said base member and acting upon said checkermeans which is thereby urged to move in a direction for engaging withsaid latch member.

References Cited UNITED STATES PATENTS 1,060,019 4/1913 Pederson 292-993,123,390 3/ 1-964 Sandor et al. 292280 3,416,826 12/1968 Putsch et al.292-198 3,415,559 12/1968 Jeavons 2922l6 FOREIGN PATENTS 482,149 6/ 3Italy 292-201 RICHARD E. MOORE, Primary Examiner

